BUFFER_HANDLE mqtt_codec_subscribe()

in src/mqtt_codec.c [925:988]

• 57 lines of code
• 11 McCabe index (conditional complexity)

BUFFER_HANDLE mqtt_codec_subscribe(uint16_t packetId, SUBSCRIBE_PAYLOAD* subscribeList, size_t count, STRING_HANDLE trace_log)
{
    BUFFER_HANDLE result;
    /* Codes_SRS_MQTT_CODEC_07_023: [If the parameters subscribeList is NULL or if count is 0 then mqtt_codec_subscribe shall return NULL.] */
    if (subscribeList == NULL || count == 0)
    {
        result = NULL;
    }
    else
    {
        /* Codes_SRS_MQTT_CODEC_07_026: [mqtt_codec_subscribe shall return a BUFFER_HANDLE that represents a MQTT SUBSCRIBE message.]*/
        result = BUFFER_new();
        if (result != NULL)
        {
            if (constructSubscibeTypeVariableHeader(result, packetId) != 0)
            {
                /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
                BUFFER_delete(result);
                result = NULL;
            }
            else
            {
                STRING_HANDLE sub_trace = NULL;
                if (trace_log != NULL)
                {
                    sub_trace = STRING_construct_sprintf(" | PACKET_ID: %"PRIu16, packetId);
                }
                /* Codes_SRS_MQTT_CODEC_07_024: [mqtt_codec_subscribe shall iterate through count items in the subscribeList.] */
                if (addListItemsToSubscribePacket(result, subscribeList, count, sub_trace) != 0)
                {
                    /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
                    BUFFER_delete(result);
                    result = NULL;
                }
                else
                {

                    if (trace_log != NULL)
                    {
                        STRING_concat(trace_log, "SUBSCRIBE");
                    }
                    if (constructFixedHeader(result, SUBSCRIBE_TYPE, SUBSCRIBE_FIXED_HEADER_FLAG) != 0)
                    {
                        /* Codes_SRS_MQTT_CODEC_07_025: [If any error is encountered then mqtt_codec_subscribe shall return NULL.] */
                        BUFFER_delete(result);
                        result = NULL;
                    }
                    else
                    {
                        if (trace_log != NULL)
                        {
                            (void)STRING_concat_with_STRING(trace_log, sub_trace);
                        }
                    }
                }
                if (sub_trace != NULL)
                {
                    STRING_delete(sub_trace);
                }
            }
        }
    }
    return result;
}